What Kind of Soil Will Affect Plant Growth?

Acidity

• The level of acidity or alkalinity of the soil affects the amount of nutrients some plants can extract. Measured on the pH scale, neutral soil is 7.0. Plants such as blueberries, camellias and rhododendrons grow best in acid soil, with a pH between 5.0 and 6.5. Leafy vegetables such as lettuce and many annual flowers grow best in more alkaline soils.

Texture

• Soil is made up of particles of sand, clay and silt, along with decaying plant and animal matter. Its texture depends on how much of any one particle is present. Sandy soil doesn't hold many nutrients, whereas clay soil has plenty of nutrients but is so tightly compacted, it doesn't allow air and water to pass through it easily to make those nutrients available to plants. The composition of the soil affects which plants can thrive in it.

Nutrients

• Soil is full of creatures that improve its texture and health and feed the plants grown in it. As plant debris falls to the ground or organisms die, the microlife of the soil breaks them down into nutrients that plants take up when they take up water. When gardeners add compost or manure to soil, they are feeding the soil microlife. Organic additions also bind sandy particles and loosen clay and silt particles.

Air

• Air needs to be present in soil so roots don't rot from too much water. Soils that are loose and rich in organic matter allow roots to spread easily and pull nutrients from a large area. Water enters easily but doesn't pool. Potting soils, used when planting in containers, contain relatively large pieces of pumice or perlite or both, to create plenty of air spaces. The soil won't compact, but will let the plant's roots spread quickly and take advantage of every inch of space.